An attractive underaged girl who you'd like to bang. But if you get caught banging her you'll go to jail, so she's the bait that lures you into the jail cell, hence the term jailbait. Is similar to a lolita, except the term jailbait only applies to an attractive underaged girl that you want to bang, while a lolita is an attractive underaged girl who also wants to bang you

R. Kelly's next concert is gonna be in cellblock 4 cuz' he got caught messin' with jailbait.

My neighbor's 14-year-old daughter who hangs out on the street corner in her Goth clothes and prances around her room in her underwear when she knows all the neighbors can see in her window, that slut.